1. Field of the invention:
The invention is directed to a backhoe boom lock for locking the boom to the swing frame during transporting and craning operations.
2. Description of the Prior Art:
A variety of work vehicles can be equipped with backhoes for doing excavation work. A backhoe is provided with a pivotal boom which is attached to the vehicle by a swing frame. The swing frame is provided with a vertical pivot for pivoting the backhoe about a vertical axis relative to the vehicle. The boom of the backhoe is joined to the swing frame by a horizontal pivot and can be pivoted relative to the swing frame about a horizontal axis. A dipperstick is pivotally to the boom. The positions of the swing frame relative to the vehicle, the boom relative to the swing frame, and the dipperstick relative to the boom are controlled by hydraulic cylinders. Typically, a bucket is pivotally attached to the end of the dipperstick remote from the boom. A hydraulic cylinder pivotally attached to the dipperstick is used to position the bucket relative to the dipperstick through a bucket linkage.
During transporting operations, as the vehicle is being moved from one job site to another, the boom is locked relative to the swing frame, and the swing frame locked relative to the vehicle. During craning operations, the boom is locked relative to the frame by the swing framer is not locked relative to the vehicle. Various examples of boom locks are disclosed in U.S. Pat. Nos. 4,225,282, 4,260,321 and 5,064,339.